US Patent 9390490 Method and device for testing defect using SEM

In performing a programmed-point inspection of a circuit pattern using a review SEM, stable inspection can be performed while suppressing the generation of a false report even when a variation in a circuit pattern to be inspected is large. SEM images that are obtained by sequentially imaging a predetermined circuit pattern using the review SEM are stored into a storage unit. Images that meet a set condition are selected from the stored SEM images, and averaged to create an average image (GP image). By performing pattern check by GP comparison using this GP image, an inspection can be performed while suppressing the generation of a false report even when a variation in the circuit patterns is large.